A mateable pair of electrical terminals comprises a first terminal disposed to engage at least one contact beam of a second terminal. A good electrical connection requires the terminals to exert a contact force against one another. These contact forces between mated terminals typically are derived from the resiliency of the metal from which the terminals are formed. In particular, terminals may be aligned to deflect during mating, and the resiliency of the metal will urge the deflected terminals back toward an undeflected condition, thereby generating the contact forces.
An over-insertion of two mateable connectors can cause contact beams of terminals in one of the connectors to deflect beyond a point at which they will resiliently return to an undeflected condition. This over-insertion and over-deflection may prevent the contact beams from exerting the required contact force against the mated terminal. Alternatively, such over-deflection can damage the connector housing or otherwise shorten the life of the connector.
The deflection of a contact beam which occurs during mating requires the generation of an insertion force. Similarly, the unmating of two electrically conductive terminals requires the exertion of a withdrawal force to overcome the normal contact force between the terminals.
Most electrically conductive terminals are very small, and therefore require reasonably low insertion and withdrawal forces. Consequently, it is generally easy to mate small electrical connectors having only a few pairs of mateable terminals. Many electrical connectors, however, comprise a large number of pairs of mateable terminals. The insertion force required for such multi-terminal connectors is the sum of the insertion forces of the various pairs of mated terminals therein. Thus, insertion forces increase in proportion to the number of terminals in a connector. Some electrical apparatus comprise modular subassemblies of electronic equipment having complex arrays of electrical components and a plurality of multi-terminal connectors. For example, a modular subassembly may comprise a plurality of circuit boards extending from a panel to which a plurality of multi-terminal electrical connectors are mounted. Modular subassemblies such as these may be referred to as drawers and may be insertable into a rack or cavity in an electrical or electromechanical apparatus. The various connectors mounted on the panel of the modular subassembly typically are simultaneously mated with a corresponding array of connectors in the rack. The sum of the insertion forces for the many terminals in such modular subassemblies of electronic equipment often will be very high and may require mechanical means for assisting the technician who carries out the mating.
The mating of the electrical connectors often occur at an inaccessible location within an apparatus. The technician performing this blind mating often cannot be certain that the several electrical connectors mounted to the modular subassembly are properly aligned for mating. As a result, the modular subassemblies being inserted into a rack may comprise guide means for facilitating alignment of the connectors, and the respective connectors may be floatably mounted to the panel to overcome any initial misalignment. Frictional forces of the guide means and biasing forces of the electrical connector float means further contribute to the insertion forces.
Many modular subassemblies of electronic equipment are used in aircraft, ground vehicles or machines that generate vibrations or that are subject to physical shock. As a result, the individual terminals in the complex modular assemblies must be constructed to exert high normal contact forces for achieving adequate electrical connection through all ranges of anticipated vibrations and shock. Thus, the total insertion force for such modular subassemblies or drawer connectors used in high vibration environments may be very high.
The prior art includes mechanical means for assisting the technician performing the mating of the above described modular subassemblies of electronic equipment. The prior art mating assistance means typically has included a lever for urging the modular subassembly into a rack or a cavity of the electrical or electromechanical apparatus. These simple lever arrangements typically have not been adapted to facilitate removal of these complex modular subassemblies. Thus, the technician was left to employ brute force to effect the removal or to employ available tools to assist in the initial unmating of the modular subassembly. The tools employed by technicians for attempting removal of a modular assembly can damage the subassembly of costly electronic equipment, thereby requiring down-time and increasing maintenance costs. The prior art lever apparatus for facilitating insertion of the modular subassemblies of electronic equipment has generally not included means for preventing over-insertion. In many instances, the forces generated by the lever would exceed the mating forces specified for selected terminals in the assembly or for the plastic housings in which the terminals are mounted.
The prior art has included pairs of parallel threaded means for urging a modular subassembly into a rack or the mating cavity of an apparatus. These prior art arrangements have required either the simultaneous use of two tools by the technician or alternating incremental advancement of the threaded means for slowly moving the drawer or modular subassembly into the rack or the cavity of the apparatus. These prior art multi-screw systems have required either exceptional dexterity for the technician to simultaneously use two tools, or have required a slow insertion process where alternate screws are incrementally advanced. The incremental alternate advancement of parallel screws would often skew the modular subassembly relative to the rack and thereby create the potential for damage to the expensive equipment. Systems of this type have been particularly vulnerable to either incomplete mating or over-insertion since the threaded insertion means provide no readily recognizable indication of complete insertion.
Modular subassemblies of electronic equipment and drawer connector assemblies employed in high vibration environments, such as aircraft or land vehicles may desirably include means for retaining the drawer or other such modular subassembly in the apparatus. Prior art systems of this type have included latch means that are structurally and functionally separate from any mating or unmating assistance apparatus that may also be provided.
In view of the above, it is an object of the subject invention to provide a apparatus for efficiently assisting in the mating of drawer connectors or other such modular subassemblies of electronic equipment.
It is another object of the subject invention t provide an efficient means for unmating drawer connectors and other such modular subassemblies of electronic equipment.
An additional object of the subject invention is to provide mating and unmating assistance means that ensures parallel movement of the subassembly along a mating axis.
Still a further object of the subject invention is to provide a mating and unmating assistance apparatus that further functions to retain the modular subassembly of electronic equipment in a mated condition within an apparatus.
Yet another object of the subject invention is to provide a mating and unmating apparatus for modular subassemblies of electronic equipment that is easy to employ and inexpensive to manufacture.
An additional object of the subject invention is to provide a mating and unmating system that prevents damage from over-insertion or excessive mating forces.